Bacterial translocation studied in 927 patients over 13 years

Synbiotics in Surgery for Chronic Pancreatitis: Are They Truly Effective? A Single-blind Prospective Randomized Control Trial

BACKGROUND

Postoperative infectious complications in patients undergoing pancreatic surgery are a significant cause for morbidity and mortality. Although synbiotics have beneficial effects on human health, their clinical value in surgical patients remains unclear given a paucity of applicable clinical studies.

AIM

To determine the impact of perioperative synbiotic therapy on postoperative infectious complications, morbidity and mortality in patients undergoing pancreatic surgery for chronic pancreatitis.

METHODS

A trial was conducted in patients with chronic calcific pancreatitis undergoing Frey's procedure. Group A received a specific synbiotic composition, 5 days prior and 10 days after the surgery. Group B received a placebo. Primary study endpoint was the occurrence of postoperative infection during the first 30 days. Secondary outcome measures were mortality, length of hospital stay, days in intensive care unit, and duration of antibiotic therapy. Using previously accrued data, with α of 0.05 and power 80%, the sample size was calculated as 35 patients for each group with a dropout rate of 10%.

RESULTS

Of the 79 patients enrolled, 75 completed the trial [group A (n = 39) and group B (n = 36)]. The incidence of postoperative infectious complications (12.8% vs 39%; P < 0.05), duration of antibiotics therapy (P < 0.05), and length of hospital stay (P < 0.05) were significantly lower in the synbiotic group.

CONCLUSIONS

Synbiotics significantly reduce septic complications, hospital stay, and antibiotic requirement in patients undergoing pancreatic surgery for chronic pancreatitis. Furthermore, basic and clinical research would clarify the underlying mechanisms of their therapeutic effect and define the appropriate conditions for use.

Effect of initial calorie intake via enteral nutrition in critical illness: a meta-analysis of randomised controlled trials

Introduction

Guidelines support the use of enteral nutrition to improve clinical outcomes in critical illness; however, the optimal calorie and protein intake remains unclear. The purpose of this meta-analysis was to quantitatively analyze randomised controlled trials with regard to clinical outcomes related to varying calorie and protein administration in critically ill adult patients.

Method

We searched Medline, EMBASE, and Cochrane databases to identify randomised controlled trials that compared the effects of initially different calorie and protein intake in critical illness. The risk ratio (RR) and weighted mean difference with 95% confidence intervals (CI) were calculated using random-effects models. The primary endpoint was mortality; secondary endpoints included infection, pneumonia, gastrointestinal intolerance, hospital and intensive care unit lengths of stay, and mechanical ventilation days.

Results

In the eight randomised controlled trials that enrolled 1,895 patients there was no statistical difference between the low-energy and high-energy groups in mortality (RR, 0.90; 95% CI, 0.71 to 1.15; P = 0.40), infection (RR, 1.09; 95% CI, 0.92 to 1.29; P = 0.32), or the risk of gastrointestinal intolerance (RR, 0.84; 95% CI, 0.59 to 1.19; P = 0.33). In subgroup analysis, the low-energy subgroup, fed 33.3 to 66.6% of goal energy, showed a lower mortality than the high-energy group (RR, 0.68; 95% CI, 0.51 to 0.92; P = 0.01). The improvements in mortality and gastrointestinal intolerance were absent when calorie intake was >66.6% of goal energy in the low-energy group. High-energy intake combined with high-protein intake reduced the infections (RR, 1.25; 95% CI, 1.04 to 1.52; P = 0.02); however, when the daily protein intake was similar in both groups, a high-energy intake did not decrease the infections. No statistical differences were observed in other secondary outcomes.

Conclusion

This meta-analysis indicates that high-energy intake does not improve outcomes and may increase complications in critically ill patients who are not malnourished. Initial moderate nutrient intake (33.3 to 66.6% of goal energy), compared to high energy, may reduce mortality, and a higher protein intake combined with high energy (≥0.85 g/kg per day) may decrease the infection rate. However, the contribution of energy versus protein intake to outcomes remains unknown.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0902-0) contains supplementary material, which is available to authorized users.

The impact of bacterial DNA translocation on early postoperative outcomes in Crohn's patients undergoing abdominal surgery

BACKGROUND AND AIMS

Bacterial DNA (bactDNA) translocation occurs frequently in patients with Crohn's disease and can be present in patients with a negative blood microbiological culture. We aimed to determine the effects of bactDNA translocation on postoperative outcomes in Crohn's disease patients undergoing abdominal surgery.

METHODS

Patients with Crohn's disease who underwent abdominal surgery between January 2012 and March 2014 were identified. General and postoperative outcome-related information was retrieved from a database, and the data were compared between patients with and without bactDNA translocation. Multivariate analysis was used to determine the independent effect of bactDNA translocation on postoperative morbidity.

RESULTS

One hundred and seven patients who underwent abdominal surgery were included in our study. The presence of bactDNA in blood samples was identified in 29 patients (27.1%). There was a total of 55 complications in 28 patients (26.2%). Patients with bactDNA in their blood had a mean postoperative hospital stay of 12.7±4.2 days and patients without DNA translocation had a mean postoperative hospital stay of 10.1±4.8 days (p = 0.009). The readmission rate was increased in patients with bactDNA translocation (p = 0.032). A low preoperative level of serum albumin (p = 0.024), preoperative immunosuppressive agent use (p = 0.046), and the presence of bactDNA in blood (p = 0.005) were independently associated with increased postoperative adverse outcomes.

CONCLUSIONS

Preoperative bactDNA translocation into the blood increases the incidence of postoperative adverse outcomes in patients with Crohn's disease who undergo abdominal surgery.

Feeding the gut: how, when and with what -- the metabolic issue

PURPOSE OF REVIEW

To review the literature on feeding critically ill patients with special emphasis on the intestine.

RECENT FINDINGS

Many dogmas have been questioned in the past few years. In particular, the absence of evidence for impact on outcomes in critically ill patients has been highlighted. So 'early enteral feeding', the trophic effect on intestinal mucosa in humans, 'pharmaco-nutrition', postpyloric feeding and prokinetic drugs have all been found to lack proper evidence to affect outcomes.

SUMMARY

The use of gastric feeding in critical illness is recommended. Successful gastric feeding is indicative of a functional gastrointestinal tract. Pharmacological effects of nutrients are questionable, but supplementation of deficits (glutamine, selenium, etc.) may be in the patient's best interest. A more individualized prescription of nutrition in the critically ill is advocated.

Central line-associated bloodstream infections in neonates with gastrointestinal conditions: developing a candidate definition for mucosal barrier injury bloodstream infections

OBJECTIVE

To develop a candidate definition for central line-associated bloodstream infection (CLABSI) in neonates with presumed mucosal barrier injury due to gastrointestinal (MBI-GI) conditions and to evaluate epidemiology and microbiology of MBI-GI CLABSI in infants.

DESIGN

Multicenter retrospective cohort study.

SETTING

Neonatal intensive care units from 14 US children's hospitals and pediatric facilities.

METHODS

A multidisciplinary focus group developed a candidate MBI-GI CLABSI definition based on presence of an MBI-GI condition, parenteral nutrition (PN) exposure, and an eligible enteric organism. CLABSI surveillance data from participating hospitals were supplemented by chart review to identify MBI-GI conditions and PN exposure.

RESULTS

During 2009-2012, 410 CLABSIs occurred in 376 infants. MBI-GI conditions and PN exposure occurred in 149 (40%) and 324 (86%) of these 376 neonates, respectively. The distribution of pathogens was similar among neonates with versus without MBI-GI conditions and PN exposure. Fifty-nine (16%) of the 376 initial CLABSI episodes met the candidate MBI-GI CLABSI definition. Subsequent versus initial CLABSIs were more likely to be caused by an enteric organism (22 of 34 [65%] vs 151 of 376 [40%]; P = .009) and to meet the candidate MBI-GI CLABSI definition (19 of 34 [56%] vs 59 of 376 [16%]; P < .01).

CONCLUSIONS

While MBI-GI conditions and PN exposure were common, only 16% of initial CLABSIs met the candidate definition of MBI-GI CLABSI. The high proportion of MBI-GI CLABSIs among subsequent infections suggests that infants with MBI-GI CLABSI should be a population targeted for further surveillance and interventional research.

Interactions of uroseptic Escherichia coli with renal (A-498) and gastrointestinal (HT-29) cell lines

We investigated the ability of Escherichia coli isolated from septic patients with urinary tract infection (UTI) to translocate through the gastrointestinal (GI) tract of the same patients using cell-culture models. Forty-seven hospitalized patients with urosepsis were included in this study. E. coli was isolated from their urine and blood (total 94 isolates) and investigated for genetic relatedness and interaction with the cell lines A-498 and HT-29. An initial comparison of the strains isolated from urine and blood showed that 44 out of 47 patients (94 %) had identical strains in their blood and urine. The blood isolates adhered to both cell lines, although their rate of adherence to A-498 cells was significantly higher than that to HT-29 cells (5.8±3.8 per cell vs 2.8±1.9; P<0.0001). The rate of translocation in A-498 cells was also significantly higher after 120 min (8.7×10(5) vs 2.9×10(5); P = 0.0006). Three non-identical blood isolates were unable to translocate in HT-29 cells, indicating that host immune factors might be more important than bacterial ability to translocate the GI epithelium in these patients. Our data showed that blood isolates from uroseptic patients are able to adhere to and translocate through both cell lines. This suggests that E. coli in patients with UTI may translocate from either the GI tract or the urinary tract, hence questioning the assumption that the urinary tract is the only source of septicaemia in these patients.

Detection of bacterial DNA in lymph nodes of Crohn's disease patients using high throughput sequencing

OBJECTIVE

Our aim was to determine whether or not specific microorganisms were transported selectively to lymph nodes in Crohn's disease (CD) by comparing node and mucosal microbial communities in patients and controls. We also sought evidence of dysbiosis and bacterial translocation.

DESIGN

Lymph nodes, and involved and uninvolved mucosal samples were obtained from resections of 58 patients (29 CD, eight 'other inflammatory bowel disease' (IBD) and 21 non-IBD). Universal primers targeting V1-V3 regions of bacterial 16S rRNA genes were used to amplify bacterial DNA and amplicons sequenced using high throughput sequencing. 20 patients (eight CD (28%), two other IBD (25%) and 10 non-IBD (48%)) had PCR positive nodes.

RESULTS

All samples from an individual were similar: there was no evidence of selective concentration of any microorganism in nodes. No specific microorganism was present in the nodes of all CD samples. Escherichia/Shigella were common in all patient groups but patients with ileal CD had a greater proportion of Escherichia coli reads in their nodes than other CD patients (p=0.0475). Campylobacter, Helicobacter and Yersinia were uncommon; Mycobacterium and Listeria were not detected. Dysbiosis was present in all groups but shifts were specific and no common pattern emerged.

CONCLUSIONS

It is unlikely that a single bacterium perpetuates inflammation in late stage CD; dysbiosis was common and we found no evidence of increased bacterial translocation. We believe that future studies should focus on early disease and viable bacteria in nodes, aphthous ulcers and granulomas, as they may be more relevant in the initiation of inflammation in CD.

Cytokine and radical inhibition in septic intestinal barrier failure

BACKGROUND

Breakdown of the intestinal barrier is a driving force of sepsis and multiple organ failure. Radical scavengers or cytokine inhibitors may have a therapeutic impact on intestinal failure. Therapeutic effects on different sites of small intestine and colon have not been compared. Therefore, we investigated time-dependent intestinal permeability changes and their therapeutic inhibition in colon and small intestine with an ex vivo model.

METHODS

Male Sprague-Dawley rats were either pretreated for 24 h with lipopolysaccharide (LPS) intraperitoneally alone or in combination with a radical scavenger (pyruvate or Tempol) or a cytokine inhibitor (parecoxib or vasoactive intestinal peptide). The gastrointestinal permeability was measured by time-dependent fluorescein isothiocyanate inulin diffusion using washed and everted tube-like gut segments. Blood and tissue samples were taken to investigate the development of inflammatory cytokine level (interleukin 6) in the context of cytokine inhibition and reactive oxygen species level via nicotinamide adenine dinucleotide phosphate oxidase activity in radical scavenger groups.

RESULTS

After LPS treatment, mucosal permeability was enhanced up to 170% in small intestine and colon. In the small intestine the most significant reduction in permeability was found for pyruvate and parecoxib. Treatment with vasoactive intestinal peptide and parecoxib resulted in the most pronounced reduction of permeability in the colon.

CONCLUSIONS

Our data suggest that cytokine inhibitors and radical scavengers have pronounced effects in LPS-induced disrupted intestinal barrier of the colon and small intestine. Our novel model comparing different anatomic sites and different points in time after the onset of sepsis may contribute to gain new insight into mechanisms and treatment options of sepsis-related gut mucosal breakdown.

Impact of perioperative symbiotic therapy on infectious morbidity after Hpb Surgery in jaundiced patients: a randomized controlled trial

This study aimed at evaluating whether the administration of symbiotic therapy in jaundiced patients could reduce their postoperative infectious complications. The study was conducted between November 2008 and February 2011. Jaundiced patients scheduled for elective extrahepatic bile duct resection without liver cirrhosis, intestinal malabsorption or intolerance to symbiotic therapy were randomly assigned to receive [Group A] or not [Group B] symbiotics perioperatively. The primary endpoint was the infectious morbidity rate. Forty patients were included in the analysis (20 in each group). The patients in Group B presented a higher overall morbidity (70 vs 50%) and infectious morbidity rate (50 vs 25%), but the differences were not significant. Eleven patients in Group A (Group ndA) and 13 in Group B (Group ndB) did not receive preoperative biliary drainage. The results of the two groups were comparable. Infectious complications were higher in Group B [5 (34%) vs 0, p = 0.030], while the prevalence of natural killer (NK) cells was higher in Group ndA the day before surgery (17% ± 5.1 vs 10% ± 5.3, p < 0.01) and on post-operative day (POD) 7 (13.1% ± 4.1 vs 7.7% ± 3.4, p < 0.01). The rates of lymph node colonization were similar. The symbiotic therapy failed to reduce the rate of infectious morbidity in jaundiced patients. Further studies investigating the place of symbiotic in no-drainage patients are required.

Calorie intake of enteral nutrition and clinical outcomes in acutely critically ill patients: a meta-analysis of randomized controlled trials

BACKGROUND

The appropriate calorie intake to be provided to critically ill patients via enteral nutrition (EN) remains unclear. We performed a meta-analysis of randomized controlled trials to compare the effect of initial underfeeding and full feeding in acutely critically ill patients.

MATERIALS AND METHODS

We searched the Medline, EMBASE, and Cochrane Central Register of Controlled Trials databases to identify randomized controlled trials that compared underfeeding with full feeding in critically ill patients. The primary outcome was overall mortality. The secondary outcomes included length of hospital stay, length of intensive care unit (ICU) stay, duration of mechanical ventilation, incidence of pneumonia, Clostridium difficile colitis, other infectious complications, and gastrointestinal intolerance.

RESULTS

In total, 4 studies were included in this meta-analysis. There was no significant difference in overall mortality between the underfeeding and full-feeding groups (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.74-1.19; I (2) = 26.6%; P = .61). Subgroup analysis of the underfeeding subgroup that was fed ≥33.3% of the standard caloric requirement indicated that overall mortality was significantly lower in this underfeeding subgroup than in the full-feeding group (OR, 0.63; 95% CI, 0.40-1.00; I (2) = 0%; P = .05). In contrast, no difference in overall mortality was noted between the underfeeding subgroup that was fed <33.3% of the standard caloric requirement and the full-feeding group. The length of hospital stay and length of ICU stay did not differ between the 2 groups. Moreover, no differences in other secondary clinical outcomes were noted.

CONCLUSIONS

None of the analyzed clinical outcomes for the acutely critically ill patients were significantly influenced by the calorie intake of the initial EN.

Analysis of the virulence of an atypical enteropathogenic Escherichia coli strain in vitro and in vivo and the influence of type three secretion system

Atypical enteropathogenic Escherichia coli (aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytes in vitro (Caco-2 cells) and in vivo (rabbit ileal loops) and to translocate the rat intestinal mucosa in vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potential in vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasion in vitro and in vivo and to bacterial translocation to extraintestinal sites.

The altered tight junctions: an important gateway of bacterial translocation in cachexia patients with advanced gastric cancer

Tight junctions (TJs) are the structural basis for the intestinal epithelium barrier. Increased intestinal permeability caused by variations in TJ proteins may result in bacterial translocation (BT). There is increasing evidence that BT might contribute to the occurrence and development of cancer cachexia, but the details are not known. Aims, we undertook further investigations into the pathway of BT in cancer cachexia.

RESULTS

BT-positive patients had a higher level of claudins-2 (CL-2, P=0.035) and a lower level of occludin (P=0.038) and Zonula occluden-1 (P=0.01) than BT-negative patients. Moreover, the levels of IL-6, TNF-α, and IFN-γ in BT-positive cachexia patients were higher compared with BT-negative cachexia patients (P<0.001, P=0.01, P<0.001) and BT-positive noncachexia patients (P<0.001, P=0.025, P<0.001). In the BT-positive cachexia patients, the local concentration of IL-6, TNF-α, and IFN-γ, in the middle colic vein, was higher than in the peripheral venous (P=0.04, P=0.03, P=0.038). In addition, endotoxin was detected within the small intestinal wall, and the concentration of endotoxin decreased from the mucosal side to the serosal side gradually in BT-positive patients. This study suggests that the altered TJs could be an important gateway of BT in gastric cancer cachexia and local cytokines could play a more important role than systemic cytokines in the process.

The detection of intraoperative bacterial translocation in the mesenteric lymph nodes is useful in predicting patients at high risk for postoperative infectious complications after esophagectomy

OBJECTIVE

To investigate the incidence of BT in the mesenteric lymph node and bacteremia after an esophagectomy using a bacterium-specific ribosomal RNA-targeted reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR).

BACKGROUND

There is little evidence regarding the occurrence of bacterial translocation (BT) and its correlation to postoperative infectious complications after an esophagectomy.

METHODS

Eighteen patients with esophageal cancer were studied. Mesenteric lymph nodes were harvested from the jejunal mesentery before surgical mobilization (MLN-1) and after the restoration of bowel continuity (MLN-2). Blood and sputum were also sampled before surgery (Blood-1 and Sputum-1) and on postoperative day 1 (Blood-2 and Sputum-2).

RESULTS

The detection rates of bacteria in the MLN-2 (56%) and Blood-2 (56%) were significantly higher than those in the MLN-1 (17%) and Blood-1 (22%), indicating that surgical stress induces BT. The detection rate was not different between Sputum-1 (80%) and Sputum-2 (78%). There was an 80% sequence homology between the RT-qPCR products in the MLN-2 and Blood-2, whereas the homology was only 20% between Blood-2 and Sputum-2. In the patients with positive bacteria in the MLN-2 sample, there was a greater incidence of postoperative infectious complications than in patients without bacteria in the MLN-2 sample (P = 0.04). The postoperative hospital stay was also longer (P = 0.037) for patients with positive bacteria in the MLN-2 sample.

CONCLUSIONS

BT frequently occurs during esophagectomies, and postoperative bacteremia is likely to be gut-derived. Patients with positive bacteria in the MLN-2 sample should be carefully managed because these patients are more susceptible to postoperative infectious complications.

An occurrence of sepsis during inpatient fecal disimpaction

Functional constipation is a common pediatric problem that is often treated through well-established algorithms. Fecal disimpaction is the initial therapeutic step, and severe cases require hospitalization for intensive therapies. We describe a significant unexpected complication of this common clinical situation. An 8-year-old boy with suspected chronic functional constipation was hospitalized for disimpaction by continuous nasogastric administration of polyethylene glycol electrolyte (PEG-E) solution. On the sixth day of disimpaction, the patient abruptly developed fever, tachycardia, and tachypnea. Evaluation included blood culture, which grew Escherichia coli, and treatment with a course of appropriate antibiotics was provided. The safety of PEG-E solutions has been shown in studies of children with constipation, which made this patient's illness surprising. Several potential etiologies of his infection were considered, including bacterial translocation (BT). BT is defined as the passage of live microbes and microbial products from the gastrointestinal tract to extraintestinal sites, such as the bloodstream. It has been shown to occur in a variety of clinical conditions but is of unclear clinical significance. In this case, physical damage to the intestinal mucosa was thought to contribute to the potential occurrence of BT, and prolonged disimpaction was considered as a risk factor. E coli sepsis in a child undergoing inpatient nasogastric fecal disimpaction with PEG-E represents a clinical problem never before reported in the literature and should increase clinicians' indices of suspicion for uncommon complications of common procedures.

Central line-associated bloodstream infection in neonatal intensive care units

OBJECTIVE

Describe the epidemiology of central line-associated bloodstream infections (CLABSIs) in neonatal intensive care units (NICUs) participating in a standardized and mandatory CLABSI surveillance program.

DESIGN

Retrospective cohort. Setting. We included patients admitted (April 2007-March 2011) to 7 level II/III NICUs who developed a CLABSI (as defined by the National Healthcare Safety Network).

METHODS

CLABSIs/1,000 central line-days and device utilization ratio were calculated; χ(2) test, Student t test, Kruskal-Wallis, and Poisson regression were used.

RESULTS

Overall, 191 patients had 202 CLABSI episodes for a pooled mean rate of 4.0 CLABSIs/1,000 central line-days and a device utilization ratio of 0.20. Annual pooled mean CLABSI rates increased from 3.6 in 2007-2008 to 5.1 CLABSIs/1,000 central line-days in 2010-2011 (P - .01). The all-cause 30-day case fatality proportion was 8.9% (n = 17) and occurred a median of 8 days after CLABSI. Coagulase-negative Staphylococcus was identified in 112 (50.5%) cases. Staphylococcus aureus was identified in 22 cases, and 3 (13.6%) were resistant to methicillin. An underlying intra-abdominal pathology was found in 20% (40/202) of CLABSI cases, 50% of which were reported in the last year of study. When adjusted for mean birth weight, annual CLABSI incidence rates were independently associated with the proportion of intra-abdominal pathology (P = .007) and the proportion of pulmonary pathology (P = .016) reported.

CONCLUSION

The increase in CLABSI rates in Quebec NICUs seems to be associated with an increased proportion of cases with underlying intra-abdominal and pulmonary pathologies, which needs further investigation.

Nutrition Management of the Critically Ill Pediatric Patient

Provision of optimal nutritional support to children in the pediatric intensive care unit (PICU) is important for optimizing nutritional management, yet challenging because of a variety of factors. Previous nutritional status, degree of malnutrition, and variability in disease states differ significantly among PICU patients. Although there are numerous benefits for enteral nutrition (EN) in critically ill children, obstacles exist within the PICU that prevent the initiation and delivery of appropriate EN and parenteral nutritional (PN) support. Evidence-based nutrition care guidelines have been established to promote optimal nutrition support practice in PICU patients, including identification of those at greatest nutritional risk, initiating EN or PN in a timely manner, and providing EN as the preferred nutrition support modality for children with a functioning gastrointestinal tract. Strategies can be implemented to minimize avoidable delays or interruptions to the optimal delivery of PN and EN, including establishing nutrition support guidelines to promote consistency in practice, promoting clear and consistent communication among the PICU team via direct communication, unit rounds, and the medical record. The education of frontline PICU staff by trained professionals such as pediatric registered dietitians board certified in pediatric nutrition or nutrition support practice can also help promote improved nutritional support practice and outcomes. Specific strategies to optimize nutritional support and EN initiation and delivery at the author’s institution are also presented.

Colonic enteric nervous system analysis during parenteral nutrition

INTRODUCTION

Parenteral nutrition (PN) is a necessary therapy used to feed patients with gastrointestinal dysfunction. Unfortunately, PN results in intestinal atrophy and changes to host immune function. PN may also induce additional effects on gut motility that we hypothesized would result from changes in the enteric nervous system.

METHODS

Mice received an intravenous (i.v.) catheter and were randomized to chow (n = 5), i.v. PN (n = 6), or i.v. PN + bombesin (BBS, 15 μg/kg, 3×/d) (n = 6) for 5 d. Colons were removed and dissected to measure the length and circumference. Enteric neuronal density and neurotransmitter expression were determined by co-immunostaining whole-mount tissue with Hu and neuronal nitric oxide synthase (nNOS).

RESULTS

The number of myenteric neurons expressing Hu and nNOS increased per unit length in the mid-colon during PN treatment compared with chow. This increase was abrogated by the addition of BBS to the PN regimen. However, the percentage of nNOS-expressing neurons was not significantly altered by PN. Morphometric analysis revealed a decrease in the length and circumference of the colon during PN administration that was partially normalized by supplementation of PN with BBS. A significant reduction in total fecal output was observed in PN animals compared with chow and was increased by mice receiving BBS in addition to PN.

CONCLUSIONS

PN causes a constriction of the bowel wall, reducing not only the length but also the circumference of the colon. These changes cause a condensation of enteric neurons but no difference in neurotransmitter expression. BBS supplementation partially restores the constriction and increases the fecal output during PN treatment compared with PN treatment alone.

The effects of perioperative probiotic treatment on serum zonulin concentration and subsequent postoperative infectious complications after colorectal cancer surgery: a double-center and double-blind randomized clinical trial

BACKGROUND

Zonulin is a newly discovered protein that has an important role in the regulation of intestinal permeability. Our previous study showed that probiotics can decrease the rate of infectious complications in patients undergoing colectomy for colorectal cancer.

OBJECTIVE

The objective was to determine the effects of the perioperative administration of probiotics on serum zonulin concentrations and the subsequent effect on postoperative infectious complications in patients undergoing colorectal surgery.

DESIGN

A total of 150 patients with colorectal carcinoma were randomly assigned to the control group (n = 75), which received placebo, or the probiotics group (n = 75). Both the probiotics and placebo were given orally for 6 d preoperatively and 10 d postoperatively. Outcomes were measured by assessing bacterial translocation, postoperative intestinal permeability, serum zonulin concentrations, duration of postoperative pyrexia, and cumulative duration of antibiotic therapy. The postoperative infection rate, the positive rate of blood microbial DNA, and the incidence of postoperative infectious complications-including septicemia, central line infection, pneumonia, urinary tract infection, and diarrhea-were also assessed.

RESULTS

The infection rate was lower in the probiotics group than in the control group (P < 0.05). Probiotics decreased the serum zonulin concentration (P < 0.001), duration of postoperative pyrexia, duration of antibiotic therapy, and rate of postoperative infectious complications (all P < 0.05). The p38 mitogen-activated protein kinase signaling pathway was inhibited by probiotics.

CONCLUSIONS

Perioperative probiotic treatment can reduce the rate of postoperative septicemia and is associated with reduced serum zonulin concentrations in patients undergoing colectomy. We propose a clinical regulatory model that might explain this association. This trial was registered at http://www.chictr.org/en/ as ChiCTR-TRC-00000423.

The relation of the level of serum anti-TF, -Tn and -alpha-Gal IgG to survival in gastrointestinal cancer patients

OBJECTIVE

To evaluate the relation of the level of serum anti-TF, -Tn and -αGal carbohydrate antibodies to survival in gastrointestinal cancer patients.

METHODS

The level of anti-TF (Thomsen-Friedenreich antigen), -Tn and -αGal IgG was analysed in the serum of patients with gastric (n = 83) and colorectal (n = 51) cancers in the long-term follow-up, using ELISA with polyacrylamide glycoconjugates. To evaluate overall survival and the risk of death, the Kaplan-Meier method and the Cox proportional hazards model were used in the univariate analysis of patients groups.

RESULTS

A significantly better survival was observed: (1) in patients with an increased level of anti-TF antibodies (all, stage III, T2-4, N1-2 and G3; P = 0.004-0.038, HR = 0.16-0.46); and (2) in patients with an increased level of anti-Tn antibodies (G1-2 tumors; P = 0.034-0.042, HR = 0.34-0.47). A significantly worse survival was observed in gastrointestinal, gastric and colorectal groups with an increased level of serum anti-αGal antibodies. This association depended on the patho-morphology of tumors (all, stages I-II, III, T2-4, N0, N1-2 and G1-2; P = 0.006-0.048, HR = 1.99-2.33). In the combined assessment of the anti-TF and -αGal antibodies level of the whole gastrointestinal group (n = 53), P = 0.002, HR = 0.25, 95% CI 0.094-0.655. In the follow-up, the survival time was shorter in patients whose level of anti-αGal antibodies rose (P = 0.009-0.040, HR = 2.18-4.27). The level of anti-TF antibodies inversely correlated with neutrophil/lymphocyte ratio (NLR, r = - 0.401, P = 0.004, n = 49). Patients with a higher level of anti-αGal antibodies and NLR values demonstrated a significantly worse survival (P = 0.009, HR = 2.98, n = 48).

CONCLUSIONS

The preoperative levels of anti-TF, -Tn and -αGal antibodies and their dynamics are of prognostic significance. The method for the determination of circulating anti-carbohydrate antibodies may be a useful supplement in clinical outcome assessment.

Probiotics, prebiotics, synbiotics: is there enough evidence to support their use in colorectal cancer surgery?

BACKGROUND/AIMS

Pro-/pre-/synbiotics supplementation seems to provide beneficial effects in various aspects of abdominal pathology. Skepticism exists with respect to their effects on colorectal cancer (CRC) patients. This review presents the potential clinical applications of pro-/pre-/synbiotics in CRC surgery.

METHODS

A literature search of electronic databases was conducted and all studies published on 'probiotics', 'prebiotics' and 'synbiotics' were collected. Among them, the ones referring to CRC and which had any clinical relevance offering information on perioperative parameters were used.

RESULTS

Incorporation of pre-/pro-/synbiotic formulations in the preoperative mechanical bowel preparation cannot be supported by the current evidence. Limited clinical studies may be promising in supporting their potentially protective role against postoperative infectious complications. Encouraging are the results on their protective role against adjuvant (chemo)radiation-induced diarrhea. Such supplementation may also hold promise to improve postcolectomy gastrointestinal related quality of life.

CONCLUSIONS

Despite the positive results and plethora of agents, bacterial combinations and concentrations, the inconsistency in administration, the inhomogeneity of comparison groups and lack of stringent clinical endpoints remain obstacles in the effort to establish a definitive clinical strategy at this time. Further work is warranted to gain a keen understanding of their clinical value in CRC patients.

Total parenteral nutrition induces a shift in the Firmicutes to Bacteroidetes ratio in association with Paneth cell activation in rats

The use of total parenteral nutrition (TPN) in the treatment of critically ill patients has been the subject of debate because it has been associated with disturbances in intestinal homeostasis. Important factors in maintaining intestinal homeostasis are the intestinal microbiota and Paneth cells, which exist in a mutually amendable relationship. We hypothesized that the disturbed intestinal homeostasis in TPN-fed individuals results from an interplay between a shift in microbiota composition and alterations in Paneth cells. We studied the microbiota composition and expression of Paneth cell antimicrobial proteins in rats receiving TPN or a control diet for 3, 7, or 14 d. qPCR analysis of DNA extracts from small intestinal luminal contents of TPN-fed rats showed a shift in the Firmicutes:Bacteroidetes ratio in favor of Bacteroidetes after 14 d (P < 0.05) compared with the control group. This finding coincided with greater staining intensity for lysozyme and significantly greater mRNA expression of the Paneth cell antimicrobial proteins lysozyme (P < 0.05), rat α-defensin 5 (P < 0.01), and rat α-defensin 8 (P < 0.01). Finally, 14 d of TPN resulted in greater circulating ileal lipid-binding protein concentrations (P < 0.05) and greater leakage of horseradish peroxidase (P < 0.01), which is indicative of enterocyte damage and a breached intestinal barrier. Our findings show a shift in intestinal microbiota in TPN-fed rats that correlated with changes in Paneth cell lysozyme expression (r(s) = -0.75, P < 0.01). Further studies that include interventions with microbiota or nutrients that modulate them may yield information on the involvement of the microbiota and Paneth cells in TPN-associated intestinal compromise.

Feeding administration of Daikenchuto suppresses colitis induced by naive CD4+ T cell transfer into SCID mice

BACKGROUND AND AIMS

Daikenchuto, a traditional Japanese herbal medicine, suppresses bacterial translocation by improvement of gastrointestinal motility and blood flow. As Daikenchuto reportedly reduces gastrointestinal inflammatory activity by these mechanisms, we analyzed whether Daikenchuto suppresses experimental colitis and reduces inflammatory cytokine expression in a mouse model.

METHODS

Colitis was induced by transfer of naive CD4(+) T cells of BALB/c mice into SCID mice, and mice were given either control or 2.7 % Daikenchuto-containing feed. We investigated body weight, clinical symptoms, histological changes, and Th1- and Th17-cytokine expression. Cytokine mRNA expression was analyzed using real-time RT-PCR. The ratio of IL-17(+) and IFN-γ(+) CD4(+) T cells were analyzed by flow cytometry.

RESULTS

Daikenchuto delayed the development of colitis and significantly reduced the histological inflammation scores. Analyses of cytokine mRNA revealed that Th17 cytokines were significantly decreased in colons of mice that received Daikenchuto. Absolute numbers of IL-17(+) or IFN-γ(+) CD4(+) T cells per colon were less in mice receiving Daikenchuto than in mice that received control feed, as both groups received naive CD4(+) T cells to induce colitis.

CONCLUSIONS

We demonstrated that feeding administration of Daikenchuto suppresses colitis induced by naive CD4(+) T cell transfer into SCID mice. Daikenchuto may show clinical benefit in the treatment of human inflammatory bowel disease and further studies are warranted.

Lactobacillus plantarum 299v does not reduce enteric bacteria or bacterial translocation in patients undergoing colon resection

BACKGROUND

Probiotics may exert beneficial effects in the gastrointestinal tract. This randomized trial investigated the effect of the probiotic Lactobacillus plantarum 299v on the intestinal load of potentially pathogenic bacteria, bacterial translocation, and cell proliferation in elective colon surgery.

METHODS

Seventy-five patients were randomized to pre- and postoperative oral intake of Lactobacillus plantarum 299v or placebo. Rectal swabs and mucosal biopsies were taken before the start of intake, after 1 week, at surgery, and after 6 days, weeks, and months. Viable counts were quantified for clostridia, Enterobacteriaceae, Gram-negative anaerobes, and lactobacilli. Bacterial translocation was determined by the analysis of bacterial DNA genes in mesenteric lymph nodes. Ki-67 was used as a marker of cell proliferation in normal mucosa and tumor.

RESULTS

Lactobacillus plantarum 299v was given without adverse effects. Lactobacillus plantarum 299v as well as Enterobacteriaceae and Gram-negative anaerobes increased in the colon 1 week after the administration of Lactobacillus plantarum 299v. There were no significant differences between patients receiving Lactobacillus plantarum 299v and placebo in the incidence of bacterial translocation (27 vs. 13%) and postoperative complications (16 vs. 31%).

CONCLUSIONS

Lactobacillus plantarum 299v was established in the intestine, but no inhibitory effect on enteric bacteria, bacterial translocation, or postoperative complications was found. The mechanism behind the protective effects of probiotics found in animal and some human studies remain elusive and require further explorations. No adverse effects were recorded after the administration of high doses of Lactobacillus plantarum 299v.

Gut-origin sepsis: evolution of a concept

The concept of bacterial translocation and gut-origin sepsis as a cause of systemic infectious complications and the multiple organ dysfunction syndrome (MODS) in surgical and ICU patients has emerged over the last several decades, although the exact clinical relevance of these phenomena continues to be debated. Thus, the goal of this review is to trace the evolution of gut-origin sepsis and gut-induced MODS and put these disorders and observations into clinical perspective. Additionally, the mechanisms leading to gut-derived complications are explored as well as therapeutic options to limit or prevent these complications. From this work, several major conclusions emerge. First, that bacterial translocation occurs clinically and is responsible for increased infectious complications in patients undergoing major abdominal surgery. However, the phenomenon of bacterial translocation is not sufficient to explain the development of MODS in ICU patients. Instead, the development of MODS in these high-risk patients is likely due to gut injury and the systemic spread of non-microbial, tissue-injurious factors that reach the systemic circulation via the intestinal lymphatics. These observations have resulted in the gut-lymph hypothesis of MODS.

Intestinal adaptation is stimulated by partial enteral nutrition supplemented with the prebiotic short-chain fructooligosaccharide in a neonatal intestinal failure piglet model

BACKGROUND

Butyrate has been shown to stimulate intestinal adaptation when added to parenteral nutrition (PN) following small bowel resection but is not available in current PN formulations. The authors hypothesized that pre- and probiotic administration may be a clinically feasible method to administer butyrate and stimulate intestinal adaptation.

METHODS AND MATERIALS

Neonatal piglets (48 hours old, n = 87) underwent placement of a jugular catheter and an 80% jejunoileal resection and were randomized to one of the following treatment groups: control (20% standard enteral nutrition/80% standard PN), control plus prebiotic (10 g/L short-chain fructooligosaccharides [scFOS]), control plus probiotic (1 × 10(9) CFU Lactobacillus rhamnosus GG [LGG]), or control plus synbiotic (scFOS + LGG). Animals received infusions for 24 hours, 3 days, or 7 days, and markers of intestinal adaptation were assessed.

RESULTS

Prebiotic treatment increased ileal mucosa weight compared with all other treatments (P = .017) and ileal protein compared with control (P = .049), regardless of day. Ileal villus length increased in the prebiotic and synbiotic group (P = .011), regardless of day, specifically due to an increase in epithelial proliferation (P = .003). In the 7-day prebiotic group, peptide transport was upregulated in the jejunum (P = .026), whereas glutamine transport was increased in both the jejunum and colon (P = .001 and .003, respectively).

CONCLUSIONS

Prebiotic and/or synbiotic supplementation resulted in enhanced structure and function throughout the residual intestine. Identification of a synergistic prebiotic and probiotic combination may enhance the promising results obtained with prebiotic treatment alone.

Effect of high-dose methotrexate chemotherapy on intestinal Bifidobacteria, Lactobacillus and Escherichia coli in children with acute lymphoblastic leukemia

High-dose methotrexate (HDMTX) chemotherapy is generally accepted as an effective method for the treatment and prevention of extramedullary leukemia in children. However, it is unknown whether HDMTX chemotherapy kills intestinal bacteria on a large scale, thus causing dysbacteriosis, which may in turn influence the progress or prognosis of leukemia. The aim of this study was to examine changes in intestinal flora in children with acute lymphoblastic leukemia (ALL) treated with HDMTX chemotherapy. Bacterial DNA in stool from 36 healthy children and 36 ALL children were tested at A(260) with a spectrophotometer before and after HDMTX chemotherapy. The primers of Bifidobacteria, Lactobacillus and Escherichia coli were designed according to the 16SrRNA/DNA bacterial sequences. Bacteria were qualitatively and quantitatively confirmed by routine polymerase chain reaction (PCR) and fluorescent quantitative PCR, respectively. Our data showed that the total amount of flora in the stools of children with ALL was decreased by 29.6% compared with healthy children (P < 0.01). The total amount of flora in the stools of children with ALL on the third and seventh days after chemotherapy were 1496.5 ± 577.1 and 1966.6 ± 598.3 ng/μL, respectively, which was notably less than before chemotherapy (2436.3 ± 768.6 ng/μL). The amount of Bifidobacteria, Lactobacillus and E. coli in the intestinal tract in the ALL group after chemotherapy had an apparent change, which decreased most clearly on the third day, and partially recovered on the seventh day after chemotherapy. HDMTX chemotherapy can cause intestinal dysbacteriosis in children with ALL. The amount of Bifidobacteria, Lactobacillus and E. coli decreased significantly compared with the control group.

Mast cells trigger epithelial barrier dysfunction, bacterial translocation and postoperative ileus in a mouse model

BACKGROUND

Abdominal surgery involving bowel manipulation commonly results in inflammation of the bowel wall, which leads to impaired intestinal motility and postoperative ileus (POI). Mast cells have shown to play a key role in the pathogenesis of POI in mouse models and human studies. We studied whether mast cells contribute to the pathogenesis of POI by eliciting intestinal barrier dysfunction.

METHODS

C57BL/6 mice, and two mast cell-deficient mutant mice Kit(W/W-v) , and Kit(W-sh/W-sh) underwent laparotomy (L) or manipulation of the small bowel (IM). Postoperative inflammatory infiltrates and cytokine production were assessed. Epithelial barrier function was determined in Ussing chambers, by measuring transport of luminal particles to the vena mesenterica, and by assessing bacterial translocation.

KEY RESULTS

In WT mice, IM resulted in pro-inflammatory cytokine and chemokine production, and neutrophil extravasation to the manipulated bowel wall. This response to IM was reduced in mast cell-deficient mice. IM caused epithelial barrier dysfunction in WT mice, but not in the two mast cell-deficient strains. IM resulted in a decrease in mean arterial pressure in both WT and mast cell-deficient mice, indicating that impaired barrier function was not explained by tissue hypoperfusion, but involved mast cell mediators.

CONCLUSIONS & INFERENCES

Mast cell activation during abdominal surgery causes epithelial barrier dysfunction and inflammation of the muscularis externa of the bowel. The impairment of the epithelial barrier likely contributes to the pathogenesis of POI. Our data further underscore that mast cells are bona fide cellular targets to ameliorate POI.

Bacterial translocation in abdominal trauma and postoperative infections

BACKGROUND

Bacterial translocation (BT) describes the passage of bacteria residing into the gastrointestinal tract, through the intestinal mucosa barrier to sterile tissues such as mesenteric lymph nodes (MLN) and other organs. This phenomenon has not been thoroughly studied in patients with trauma to date, and an association between BT and postoperative infection has not been well established so far.

METHODS

MLNs from 36 patients with abdominal trauma were removed during laparotomy and cultured to detect BT. Postoperative infectious complications in these patients were registered, and both phenotypical and molecular typings (through multilocus sequencing) were carried out for microorganisms isolated from MLN and postoperative infection sites. Associations between clinical variables, BT presence, and postoperative infection development were established.

RESULTS

BT was detected in 33% of the patients (n = 12). Postoperative infections were present in 22.2% of the patients (n = 8). A significant statistical difference was found between postoperative infections in patients with BT evidence (41.6%), when compared with patients without BT (12.5%; p = 0.047). Bacteria isolated from infection sites were the same as those cultured in MLN in 40% of the cases (n = 2 of 5), allowing us to establish causality between BT and postoperative infection.

CONCLUSIONS

There is higher risk of BT in trauma patients, and it is associated with a significant increase of postoperative infections. An abdominal trauma index ≥10 was found to be associated with the development of BT. This is the first study describing BT among patients with abdominal trauma, where causality is confirmed at molecular level.

Intestinal barrier function in patients undergoing colectomy

AIM

The aim of this pilot study was to determine whether the type of approach (open or laparoscopic) and the order of devascularization during laparoscopic colectomy affect intestinal barrier function, local inflammatory response and clinical outcome.

METHOD

Twenty-two patients undergoing elective colectomy from April 2006 to July 2008 were randomized to two sequences of vascular ligation, starting with either the inferior mesenteric artery or the ileocolic artery. Eighteen patients scheduled for open surgery served as a prospective control group. To assess the intestinal barrier function, release of intestinal fatty-acid binding protein (I-FABP; a marker of mucosal injury and ischaemia) was measured pre- and postoperatively. Mesenteric lymph nodes were harvested to assess the expression of inflammatory mediator-related genes using multiplex ligation probe amplification. The study was registered under NTR1025.

RESULTS

Laparoscopic devascularization starting at the ileocolic artery resulted in a significantly increased excretion of I-FABP over time (P = 0.002). In this group, the I-FABP levels were significantly increased on postoperative days 1 and 3 compared with preoperative values (P = 0.011 and P = 0.001, respectively). There were no differences in expression of inflammatory mediator-related genes or postoperative morbidity among the groups.

CONCLUSIONS

In this pilot study, devascularization commencing at the ileocolic artery during laparoscopic colectomy was associated with prolonged intestinal mucosal ischaemia.

Gastrointestinal dysmotility: clinical consequences and management of the critically ill patient

Gastrointestinal dysmotility is a common feature of critical illness, with a number of significant implications that include malnutrition secondary to reduced feed tolerance and absorption, reflux and aspiration resulting in reduced lung function and ventilator-associated pneumonia, bacterial overgrowth and possible translocation causing nosocomial sepsis. Prokinetic agent administration can improve gastric emptying and caloric delivery, but its effect on nutrient absorption and clinical outcomes is, as yet, unclear. Postpyloric delivery of nutrition has not yet been demonstrated to increase caloric intake or improve clinical outcomes.

Starvation compromises Paneth cells

Lack of enteral feeding, with or without parenteral nutritional support, is associated with increased intestinal permeability and translocation of bacteria. Such translocation is thought to be important in the high morbidity and mortality rates of patients who receive nothing by mouth. Recently, Paneth cells, important constituents of innate intestinal immunity, were found to be crucial in host protection against invasion of both commensal and pathogenic bacteria. This study investigates the influence of food deprivation on Paneth cell function in a mouse starvation model. Quantitative PCR showed significant decreases in mRNA expression of typical Paneth cell antimicrobials, lysozyme, cryptdin, and RegIIIγ, in ileal tissue after 48 hours of food deprivation. Protein expression levels of lysozyme and RegIIIγ precursor were also significantly diminished, as shown by Western blot analysis and IHC. Late degenerative autophagolysosomes and aberrant Paneth cell granules in starved mice were evident by electron microscopy, Western blot analysis, and quantitative PCR. Furthermore, increased bacterial translocation to mesenteric lymph nodes coincided with Paneth cell abnormalities. The current study demonstrates the occurrence of Paneth cell abnormalities during enteral starvation. Such changes may contribute to loss of epithelial barrier function, causing the apparent bacterial translocation in enteral starvation.

Cycled enteral antibiotics reduce sepsis rates in paediatric patients on long-term parenteral nutrition for intestinal failure

BACKGROUND

Long-term parenteral nutrition has transformed the prognosis for children suffering from intestinal failure. However, parenteral nutrition itself is associated with considerable morbidity and mortality including that caused by sepsis.

AIM

To examine a strategy of cycled enteral antibiotics in reducing the incidence of sepsis in paediatric intestinal failure patients.

METHODS

Retrospective analysis of the incidence of sepsis rates of patients on long-term parenteral nutrition, at a tertiary paediatric hospital. Patients were separated into those who received cycled enteral antibiotics and a control group. Sepsis rates before and during cycled enteral antibiotics were compared with comparable timeframes between the cycled enteral antibiotics and control groups. Central venous catheter removal rates were also compared.

RESULTS

Fifteen patients (eight cycled enteral antibiotics, & seven controls) received 9512 parenteral nutrition days, with a total of 132 sepsis episodes. All eight patients of the treatment group demonstrated a decrease in the frequency of episodes of sepsis following the introduction of cycled enteral antibiotics. The cycled enteral antibiotics group had a significant reduction in infection rate during the treatment period (from 2.14 to 1.06 per 100 parenteral nutrition days, P = 0.014: median effect size -1.04 CI 95%-1.93, -0.22), whereas the controls had no significant change (1.91 - 2.36 per 100 parenteral nutrition days P = 0.402: median effect size 0.92 CI 95%-1.96, 4.17). The central venous catheter survival rates increased in the cycled enteral antibiotics group from 0.44 central venous catheter removals per 100 parenteral nutrition days to 0.27 central venous catheter removals per 100 parenteral nutrition days, although this was not statistically significant.

CONCLUSIONS

Cycled enteral antibiotics significantly reduced the rate of sepsis in a small group of paediatric intestinal failure patients. Larger well-designed prospective studies are warranted to further explore this finding.

Randomized trial of initial trophic versus full-energy enteral nutrition in mechanically ventilated patients with acute respiratory failure

OBJECTIVE

Enteral nutrition is provided to mechanically ventilated patients who cannot eat normally, yet the amount of support needed is unknown. We conducted this randomized, open-label study to test the hypothesis that initial low-volume (i.e., trophic) enteral nutrition would decrease episodes of gastrointestinal intolerance/complications and improve outcomes as compared to initial full-energy enteral nutrition in patients with acute respiratory failure.

DESIGN

Randomized, open-label study.

PATIENTS

A total of 200 patients with acute respiratory failure expected to require mechanical ventilation for at least 72 hrs.

INTERVENTIONS

Patients were randomized to receive either initial trophic (10 mL/hr) or full-energy enteral nutrition for the initial 6 days of ventilation.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was ventilator-free days to day 28. Baseline characteristics were similar between the 98 patients randomized to trophic and the 102 patients randomized to full-energy nutrition. At enrollment, patients had a mean Acute Physiology and Chronic Health Evaluation II score of 26.9 and a PaO2/FiO2 ratio of 182 and 38% were in shock. Both groups received similar durations of enteral nutrition (5.5 vs. 5.1 days; p = .51). The trophic group received an average of 15.8% ± 11% of goal calories daily through day 6 compared to 74.8% ± 38.5% (p < .001) for the full-energy group. Both groups had a median of 23.0 ventilator-free days (p = .90) and a median of 21.0 intensive-care-unit-free days (p = .64). Mortality to hospital discharge was 22.4% for the trophic group vs. 19.6% for the full-energy group (p = .62). In the first 6 days, the trophic group had trends for less diarrhea (19% vs. 24% of feeding days; p = .08) and significantly fewer episodes of elevated gastric residual volumes (2% vs. 8% of feeding days; p < .001).

CONCLUSION

Initial trophic enteral nutrition resulted in clinical outcomes in mechanically ventilated patients with acute respiratory failure similar to those of early full-energy enteral nutrition but with fewer episodes of gastrointestinal intolerance.

Dramatic changes of the gut flora immediately after severe and sudden insults

BACKGROUND

The gut flora is crucially involved in host homeostasis. However, the changes in the gut flora during the early phase of a critical illness are unknown.

AIMS

We investigated the changes in the gut flora at an early phase of severe insult in critically ill patients.

METHODS

Fifteen patients who experienced a sudden and severe insult were studied, along with 12 healthy volunteers as the control group. Fecal samples were acquired from the subjects by swabs of the rectum within 6 h after admission to the emergency room (day 0). Samples were serially collected from patients until day 14. Samples were also collected from control subjects.

RESULTS

On day 0, total bacterial counts were decreased to one-thousandth the number of the control subjects, in particular, obligate anaerobes and Lactobacillus were significantly decreased. In addition, on day 0, the major short-chain fatty acids of the patients were significantly lower than those of the control subjects. The gut flora and the concentrations of major short-chain fatty acids did not recover to normal levels. In contrast, Enterococcus and Pseudomonas increased during the study period.

CONCLUSIONS

The gut flora in critically ill patients changed immediately after a severe insult. The concentrations of the three major short-chain fatty acids were immediately decreased in tandem with the destruction of the gut flora. The gut flora and the concentration of major short-chain fatty acids did not improve during the first 2 weeks after hospital admission. At the same time, the number of harmful bacteria gradually increased.

Influence of prophylactic probiotics and selective decontamination on bacterial translocation in patients undergoing pancreatic surgery: a randomized controlled trial

Bacterial translocation (BT) is suspected to play a major role in the development of infections in surgical patients. However, the clinical association between intestinal barrier dysfunction, BT, and septic morbidity has remained unconfirmed. The objective of this study was to study BT in patients undergoing major abdominal surgery and the effects of probiotics, selective decontamination of the digestive tract (SDD), and standard treatment on intestinal barrier function. In a randomized controlled setting, 30 consecutive patients planned for elective pylorus-preserving pancreaticoduodenectomy (PPPD) were allocated to receive perioperatively probiotics, SDD, or standard treatment. To assess intestinal barrier function, intestinal fatty acid-binding protein (mucosal damage) and polyethylene glycol recovery (intestinal permeability) in urine were measured perioperatively. BT was assessed by real-time polymerase chain reaction and multiplex ligation-dependent probe amplification (MLPA) in mesenteric lymph nodes (MLNs) harvested early (baseline control) and at the end of surgery ("end-of-surgery" MLNs, after 3h in PPPD patients). Polymerase chain reaction detected bacterial DNA in 18 of 27 end-of-surgery MLNs and in 13 of 23 control MLNs (P = 0.378). Probiotics and SDD had no significant effect on the number of positive MLNs or the change in bacterial DNA during operation. Multiplex ligation-dependent probe amplification analysis showed significantly increased expression of only 4 of 30 inflammatory mediator-related genes in end-of-surgery compared with early sampled MLN (P < 0.05). Polyethylene glycol recovery was unaffected by operation, probiotics and SDD as compared with standard treatment. Intestinal fatty acid-binding protein levels were increased shortly postoperatively only in patients treated with SDD (P = 0.02). Probiotics and SDD did not influence BT, intestinal permeability, or inflammatory mediator expression. Bacterial translocation after abdominal surgery may be part of normal antigen-sampling processes of the gut.

Intestinal mast cells in gut inflammation and motility disturbances

Mast cells may be regarded as prototypes of innate immune cells that can be controlled by neuronal mediators. Their activation has been implicated in many types of neuro-inflammatory responses, and related disturbances of gut motility, via direct or indirect mechanisms that involve several mechanisms relevant to disease pathogenesis such as changes in epithelial barrier function or activation of adaptive or innate immune responses. Here we review the evidence for the involvement of mast cells in the inflammation of the bowel wall caused by bowel manipulation that leads to motility disturbances such as postoperative gastroparesis and ileus. Also in IBD there is substantial evidence for the involvement of mast cells and a mast cell-mediated neuroimmune interaction showing an increased number and an increased degranulation of mast cells. We discuss the potential of mast cell inhibition as a bona fide drug target to relief postoperative ileus. Further research on mast cell-related therapy either by stabilizing the mast cells or by blocking specific mast cell mediators as adjunctive therapy in IBD is encouraged, bearing in mind that several drugs currently used in the treatment of IBD possess properties affecting mast cell activities. This article is part of a Special Issue entitled: Mast cells in inflammation.

The renal cyst infection caused by Salmonella enteritidis in a patient with autosomal dominant polycystic kidney disease: how did this pathogen come into the renal cysts?

A 40-year-old Japanese man was admitted to our hospital for investigation of fever and right flank pain starting after watery diarrhea. Salmonella enteritidis was cultured from samples of stool and blood. Although his diarrhea subsided soon, high fever persisted and flank pain got worse. Magnetic resonance imaging (MRI) revealed four areas of abnormal intensity in renal cysts and computed tomography showed the same findings. Renal cysts infection was diagnosed. After ultrasound-guided aspiration of these cysts, his fever subsided. Culture of each aspirate grew Salmonella enteritidis. Although the route of cyst infection in ADPKD generally remains unclear, the clinical course of our patient may indicate that gastrointestinal tract infection progressed to renal cyst infection when bacteremia occurred due to bacterial translocation.